NEW DELHI: The Indian Army is on track to become the first military force worldwide to integrate ramjet-powered 155 mm artillery shells into its operations. This development represents a significant step forward in enhancing the capabilities of existing artillery systems through indigenous technology.
Development and Collaboration:
The project stems from India’s push for self-reliance in defense under the Atmanirbhar Bharat initiative. The Indian Institute of Technology (IIT) Madras has partnered with the Indian Army, with funding and support provided by the Army Technology Board. This collaboration has focused on adapting ramjet propulsion, a technology commonly found in missiles, to artillery ammunition. Developmental trials have been conducted successfully at the Pokhran Field Firing Ranges in Rajasthan, with refinements ongoing to ensure reliability in various operational conditions.
Technical Features:
Ramjet propulsion operates as an air-breathing engine that does not require compressors or turbines. The shell is initially propelled by a standard artillery gun to reach speeds around Mach 2, at which point incoming air is compressed through the intake system. Fuel is then ignited, generating sustained thrust to extend the shell’s flight. This allows the ammunition to achieve speeds up to Mach 3, making it challenging for adversaries to detect or counter.
A key aspect of the design is its compatibility with existing 155 mm shells and gun systems. The ramjet module can be retrofitted onto standard ammunition, enabling seamless integration without the need for new platforms. This includes systems such as the M777 ultra-light howitzer, Advanced Towed Artillery Gun System (ATAGS), Dhanush, Sharang, and K9 Vajra self-propelled howitzers. The Indian Army’s artillery inventory spans multiple calibers, including 105 mm, 122 mm, 130 mm, and 155 mm, with the latter serving as the primary standard for medium-range operations.
In terms of classification, artillery ammunition is categorized by role: light (up to 105 mm) for close support, medium (106-155 mm) for general bombardment, and heavy (over 155 mm) for targeting distant installations. The ramjet-enhanced 155 mm shells fit into the medium category but extend its effective reach significantly.
Performance Enhancements:
The primary benefit is an increase in range by 30 to 50 percent compared to conventional shells, pushing operational distances from the typical 30-40 km to 60-80 km initially, with potential for over 100 km in future iterations. This extension maintains the shell’s lethality and precision, allowing for more effective strikes without relocating artillery units.
Development efforts have addressed challenges such as achieving consistent burn rates at high speeds, efficient air intake for oxygen compression, and sustained thrust following the initial gun launch. These improvements contribute to better overall performance in diverse terrains, including mountainous and desert regions.
Strategic and Operational Implications:
This technology provides the Indian Army with enhanced flexibility for long-range engagements, including deep strikes against enemy logistics, command centers, and airfields. It supports counter-battery fire while remaining beyond the range of retaliatory artillery, which is particularly useful along contested borders. By reducing reliance on more expensive rocket systems for medium-range targets, it optimizes resource allocation and strengthens deterrence capabilities.
The plug-and-play nature of the shells allows for rapid deployment across existing fleets, minimizing training and logistical adjustments. As an indigenous solution, it reduces dependence on foreign imports and opens avenues for potential exports, positioning India as a frontrunner in advanced artillery munitions.
Global Developments and Comparisons:
While ramjet propulsion is established in missiles, its artillery application is emerging. Norway’s Nammo develops the 155 mm HE-ExR shell, targeting 150 km ranges. U.S. startup Tiberius Aerospace offers the Sceptre, a ramjet-powered precision-guided variant with self-regulating features. The U.S. Army’s XM1155 program, funded since 2019, explores similar extended-range projectiles.
India’s approach emphasizes retrofit compatibility and cost-effectiveness, distinguishing it from these efforts, which often focus on new designs.
Challenges and Future Prospects:
Development has addressed issues like mid-flight ignition stability, aerodynamic materials for Mach speeds, and fire control integration for thrust data. Future iterations may include guidance for higher precision and further range extensions.
Success could position India as a leader in artillery innovation, with potential for exports and broader applications in defense systems.
The ramjet-powered 155 mm shell project underscores India’s commitment to self-reliant defense, blending academic and military expertise to achieve technological superiority. As trials advance, this innovation promises to transform artillery operations, offering enhanced capabilities in a cost-effective manner.
(Technical details on ramjet propulsion based on inputs to The Week)
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